1. Field of the Invention
This invention relates to methods of extinguishing titanium metal fires. More particularly, this invention relates to methods of extinguishing titanium metal fires in a flowing airstream.
2. Description of the Prior Art
Titanium is a low density, high strength metal which has found increasing utilization in the aerospace industry. Although displaying excellent corrosive (oxidation) resistance at normal temperatures and air pressures, the bulk metal is subject to sustained combustion in pure oxygen and/or pressurized air once sufficient energy for ignition has been obtained. One such critical environment for titanium combustion exists in the high pressure compressor sections of gas turbine engines. Titanium has been a material of choice here for weight reduction. However, sufficient energy to cause ignition is obtainable through foreign object damage, blade rubs or strikes, or a blade failure. Once ignited, titanium is actually a very energetic metal and will burn in oxygen and/or nitrogen at a very high temperature (5300.degree. F.) as long as sufficient pressure is maintained. Many conventional extinguishants are not effective and may even be hazardous against titanium fires.
Several specific extinguishants have proven useful in combating titanium fires. Examples include the liquid extinguishant trimethoxyboroxine and the solid extinguishants sodium chloride and graphite carbon. However, no specific extinguishant for titanium fires has been designed for use in a pressurized, flowing airstream.